In a conventional mobility management method, a network and a mobile terminal are configured to perform an operation for mobility management by using the same mobility management procedure.
As shown in FIG. 1, for example, when a mobile terminal 10 has an MIP (Mobile IP) function and an edge node 30 (domain #1) of a network has an MIP FA (Foreign Agent) function, the network and the mobile terminal 10 are configured to perform the mobility management operation using an MIP procedure.
In an example of FIG. 1, an HA (domain #2) is a home agent for CMIP (Client for Mobile IP) and manages a home address of the mobile terminal 10. The HA is configured to transfer an IP packet received from the Internet to an MIP FA function 30A of the edge node 30 by way of an MIP tunnel.
The MIP FA function 30A of the edge node 30 manages a foreign address of the mobile terminal 10, and is configured to transfer the packet transmitted from the HA to the mobile terminal 10.
The mobile terminal 10 has a Mobile IP client function (CMIP), and is configured to register a foreign address in the HA, the foreign address allocated by the MIP FA Function 30A of the edge node 30.
In addition, as shown in FIG. 2, the network and the mobile terminal 10 are configured to perform the mobility management operation by using a PMIP procedure, when the mobile terminal 10 does not have the MIP function, and the edge node (domain #1) 30 of the network does not have the MIP FA function and has a PMIP (Proxy Mobile IP) client function.
In an example of FIG. 2, an HA is a home agent for PMIP and manages a home address of the mobile terminal 10. The HA is configured to transfer an IP packet received from the Internet to a PMIP client function 30B of an edge node 30 that belongs to the same domain #1 as the HA.
The PMIP client function 30B of the edge node 30 is configured to register, in the HA, an IP address of the PMIP client function 30B as a foreign address of the mobile terminal 10 and to transfer the packet transmitted from the HA to the mobile terminal 10.
In addition, a mobility management method proposed in 3GPP2 or WiMAX Forum will be described with reference to FIG. 3.
As shown in FIG. 3, in step 0, a network performs authentication processing for a mobile terminal 10.
In step 1, the mobile terminal 10 notifies an edge node 30 of a terminal function which is provided to the mobile terminal 10. Herein, a Mobile IP client function, such as “MIP v4” or “MIP v6”, an IP function, such as “IP v4” or “IP v6”, or the like is assumed for the terminal function.
In step 2, the edge node 30 determines whether to perform a mobility management operation by using the MIP FA function 30A, or to perform the mobility management operation by using the PMIP client function 38, depending on the terminal function provided to the mobile terminal 10. In step 3, the edge node 30 notifies the mobile terminal 10 of an operation method that indicates whether to perform the mobility management operation by using the MIP client function or to perform the mobility management operation by using the IP function.    Non-Patent Document 1: 3GPP2 X.S0011-002-D Version 1.0 Section 8, February 2006